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We report the fabrication of Si3N4/SiC nano/nano-composite reinforced by single-crystal low-dimensional nanostructures via spark plasma sintering of nanocomposite powders containing in-situ formed Si3N4 nanowires/nanobelts. The fabricated nanocomposite is analyzed by scanning electron microscopy, X-ray diffraction, transmission electron microscopy and selective area electron diffraction. The results show that the in-situ formed Si3N4 nanowires/nanobelts are uniformly distributed within the matrix. Such a nanocomposite could exhibit improved mechanical properties, due to the superior mechanical properties and uniform distribution of the nano-reinforcements.

Low-dimension semiconductor nanostructures were successfully synthesized by a fast, simple, and low-cost microwave method. By heating raw materials under microwave irradiation and controlled conditions, diverse nanostructures for semiconducting oxides and carbides were synthesized without extra metal catalysts. In this paper, flower-like and net structural oxide and carbide semiconductors in nanoscale have been studied in detail. Structural, morphological, and elemental analysis revealed that the as-synthesized nanostructures were highly pure and structurally uniform. The possible growth mechanisms of these nanostructures were preliminarily discussed. The temperature and the gas-phase supersaturation in their growing processes have important effects on their morphologies. The unique synthesis method may open a new way for the fabrication of self-assembled multidimensional structures, which are expected to find a wide range of important applications in nanodevices and nanocomposites.

We report for the first time the synthesis of Al-doped 6H-SiC nanowires with high yield and high quality. The nanowires were obtained by the catalyst-assisted pyrolysis of polymeric precursors with FeCl2 as the catalyst. The doping concentrations were controlled by tailoring the Al concentrations in the precursors. It was observed that the Al dopants caused red-shifts of the photoluminescence bands. The results suggest a simple technique to synthesize Al-doped SiC nanomaterials in a controlled manner. The obtained nanowires could be useful for making optical and electronic nanodevices.

A significant challenge in synthesizing nanowire/nanobelt-reinforced ceramic nanocomposites is to uniformly disperse these reinforcements. Here, we report the synthesis of amorphous silicon carbonitride powders containing in situ-formed single-crystal Si3N4 nanowires and nanobelts via the catalyst-assisted pyrolysis of a polymeric precursor. The nanowires/nanobelts are uniformly dispersed within the powder matrix. The ratio of nanomaterials to powder can be controlled by tailoring the experimental conditions. The novel powders could be useful for fabricating nanowire/nanobelt-reinforced ceramic nanocomposites.

We report the large-scale synthesis of very thin single-crystalline Si{sub 3}N{sub 4} nanobelts with high yield via catalyst-assisted pyrolysis of polymeric precursors. The obtained nanobelts, which show a perfect crystal structure and smooth surface, are up to several millimeters in length with typical width and thickness of {approx}800 nm and tens of nanometers, respectively. It is believed that the nanobelts were grown via a vapor-solid process, in which Al catalyst played a key role. This result provides a possibility for mass producing high quality, very thin Si{sub 3}N{sub 4} nanobelts. - Graphical abstract: We report the mass production of very thin single-crystalline Si{sub 3}N{sub 4} nanobelts with a high yield via catalyst-assisted pyrolysis of polymeric precursors.

Bismuth vanadate (BiVO4) is considered as a potentially attractive candidate for the O2 evolution and photodegradation of organic pollutants. In an effort to develop visible-light-driven photocatalysts with high activities, the thoroughly mesoporous BiVO4 nanofibers were fabricated via a foaming-assisted electrospinning strategy. It was found that the introduced foaming agent of diisopropyl azodiformate within the solutions plays a crucial role on the formation of thoroughly mesoporous BiVO4 nanofibers, making their growth tunable. The obtained mesoporous BiVO4 nanofibers possess well-defined one-dimensional mesoporous architectures with high purity in their morphology and a surface area of 22.5 m(2)/g, which is ∼4 times that of conventional solid counterparts (5.8 m(2)/g). Accordingly, they exhibit much higher efficient photocatalytic activities toward the degradation of rhodamine B under visible-light irradiation, which is 3 times that of conventional solid counterparts, suggesting their promising application as novel and efficient photocatalysts for water purification.

We developed and validated a robust marker toolkit for high-throughput and cost-effective screening of a large number of functional genes in wheat. Functional markers (FMs) are the most valuable markers for crop breeding programs, and high-throughput genotyping for FMs could provide an excellent opportunity to effectively practice marker-assisted selection while breeding cultivars. Here we developed and validated kompetitive allele-specific PCR (KASP) assays for genes that underpin economically important traits in bread wheat including adaptability, grain yield, quality, and biotic and abiotic stress resistances. In total, 70 KASP assays either developed in this study or obtained from public databases were validated for reliability in application. The validation of KASP assays were conducted by (a) comparing the assays with available gel-based PCR markers on 23 diverse wheat accessions, (b) validation of the derived allelic information using phenotypes of a panel comprised of 300 diverse cultivars from China and 13 other countries, and (c) additional testing, where possible, of the assays in four segregating populations. All KASP assays being reported were significantly associated with the relevant phenotypes in the cultivars panel and bi-parental populations, thus revealing potential application in wheat breeding programs. The results revealed 45 times superiority of the KASP assays in speed than gel-based PCR markers. KASP has recently emerged as single-plex high-throughput genotyping technology; this is the first report on high-throughput screening of a large number of functional genes in a major crop. Such assays could greatly accelerate the characterization of crossing parents and advanced lines for marker-assisted selection and can complement the inflexible, high-density SNP arrays. Our results offer a robust and reliable molecular marker toolkit that can contribute towards maximizing genetic gains in wheat breeding programs.

The TGW6 gene encodes a novel indole-3-acetic acid-glucose hydrolase and plays a significant role in improving thousand grain weight (TGW) and yield in rice. In the current study, a TGW6 ortholog from bread wheat chromosome 3AL was isolated and designated as TaTGW6-A1. Sequencing and alignment analysis showed that the cloned TaTGW6-A1 consists of a 987-bp intronless open reading frame. Three single-nucleotide polymorphisms (SNPs) were identified between cultivars with higher and lower TGW, forming two haplotypes, TaTGW6-A1a and TaTGW6-A1b. A derived cleaved amplified polymorphic sequence marker, TaTGW6-A1-CAPS, was developed to differentiate the two haplotypes. Linkage analysis using the wheat 90K iSelect SNP array mapped TaTGW6-A1-CAPS at 18 cM from BobWhite_c47304_56 in a RIL population derived from Zhou 8425B/Chinese Spring. A QTL for yield at the TaTGW6-A1 locus explained 17.4 % of the phenotypic variance in average yield over four environments. Association analysis on 242 Chinese and foreign cultivars indicated that TaTGW6-A1 was significantly associated with TGW. The cumulative frequency of the TaTGW6-A1a allele associated with higher TGW was approximately 80 %, indicating that the TaTGW6-A1a allele was positively selected in wheat breeding. In conclusion, TaTGW6-A1 in conjunction with its molecular marker may contribute as a valuable gene in improving yield potential in wheat.

In this work, polycrystalline WO3 nanobelts were fabricated via an electrospinning process combined with subsequent air calcination. The resultant products were characterized by X-ray diffraction, field-emission scanning electron microscopy, and high-resolution transmission electron microscopy in regard to the structures. It has been found that the applied voltage during the electrospinning process played the determined role in the formation of the WO3 nanobelts, allowing the controlled growth of the nanobelts. The ultraviolet (UV) photodetector assembled by an individual WO3 nanobelt exhibits a high sensitivity and a precise selectivity to the different wavelength lights, with a very low dark current and typical photo-dark current ratio up to 1000, which was the highest for any WO3 photodectectors ever reported. This work could not only push forward the facile preparation of WO3 nanobelts but also represent, for the first time, the possibility that the polycrystalline WO3 nanobelts could be a promising building block for the highly efficient UV photodetectors.

Silicon-on-insulator (SOI) rib waveguides with residual sidewall roughness were achieved through inductive coupled plasma reactive ion etching (ICPRIE) process. Sidewall roughness is the dominant scattering loss source. Conventional ICPRIE could result in the sidewall ripples derived from the etch/deposition cycle steps. Mixed ICPRIE process and hydrogen annealing were used to improve the sidewall roughness of SOI rib waveguides and eliminate the sidewall ripples. Scan electron microscope and atomic force microscope were used to demonstrate the surface profiles of the sidewall. The results indicated that the sidewall roughness could be low down to 0.3 nm level by optimization and combination of these two techniques and the ripples disappeared. According to the scattering theory developed by Payne and Lacey, the scattering loss could be reduced to below 0.01 dB/cm.

Poly(vinyl alcohol) (PVA)/H4SiW12O40 ultrafine fiber aggregates contained differential weight percentage of H4SiW12O40 to PVA (20, 60 and 80 wt.%, respectively) have been successfully prepared by electrospinning technique. By means of IR spectrum, wide-angle X-ray diffraction (XRD), and scanning electron microscope (SEM) techniques, the characterizations of the fiber aggregates have been reported. The photochromic property of the PVA fiber aggregates contained H4SiW12O40 has been found. The photochromic behavior of the fiber aggregates is investigated by means of UV–Vis spectra and electron spin resonance (ESR). The results show that the W atom of H4SiW12O40 is reduced via one-electron step and the color of the fiber aggregates changes from white to blue under ultraviolet irradiation. At the same time, alkoxy radicals form in PVA. The photochromism of the fiber aggregates is reversible in room condition. The ESR of the irradiated fiber aggregates indicates a conceivable photochromic mechanism.

Poly(vinyl alcohol) (PVA) fiber aggregates contained 20 and 80 wt.% H 3 PW 12 O 40 were prepared by an electrospinning method. The fiber aggregates were characterized by IR, XRD and scanning electron microscope (SEM) photographs. The results indicated that PVA could combine with H 3 PW 12 O 40 by intermolecular H-bonding. The studies of the diameter distributions indicated that the average diameter of the fibers was 370 and 520 nm for 20 and 80 wt.% H 3 PW 12 O 40 , respectively. The Brunauer–Emmett–Teller (BET) surface area increased with decreasing the average diameter of the fibers. Swelling behavior of the fiber aggregates in water was investigated. The existence of H 3 PW 12 O 40 was advantaged for the crosslinking of PVA.

In this paper, we have demonstrated the Oswald ripening growth of single-crystalline Si3N4 nanoplates. The formation of the plates involves three basic steps: formation and aggregation of the nanoparticles, grain coalescence within selective areas, and growth of one coarsened grain at the expense of the rest of the nanoparticles via an Oswald ripening process assisted by the oriented attachment mechanism. The obtained nanoplates exhibit an extremely high aspect ratio with an ultrathin thickness, flat surface, and perfect crystal structure, and they could be utilized as substrates for constructing nanodevices.

Hollow Al2O3 microsphere chain networks have been synthesized via a simple two-staged pyrolysis of a precursor using active carbon powders as the template. The obtained networks are characterized using scanning electron microscopy, X-ray diffraction, and transmission electron microscopy. The chain networks are formed by subsequent aggregation of the prior formed hollow Al2O3 microspheres. The obtained chain networks are promising for the applications in catalyst support, filtration, and other applications due to their lightweight and highly porous nature.

A self-aligned two-mask lithography process was used to define silicon-on-insulator rib waveguides and corner mirrors, which were etched using inductively coupled plasma reactive ion etching. Atomic force microscopy was used to directly measure the surface morphology of the corner mirrors for the first time. The low-temperature ultrahigh vacuum annealing was used to smooth the corner mirror surface. After annealing, the ripples of the corner mirror disappeared, and the root-mean-square roughness of the mirror surface was reduced to 9.1 nm.

In this work, we reported the energy transfer between Mn doped CdS quantum dots (Mn:CdS QDs) with the core–shell structure of MnS/ZnS/CdS and 1,3,5-tris(N-phenylbenz-imidazol-2,yl) benzene (TPBI) in inorganic/organic blend films by steady-state and time-resolved photoluminescence (PL) spectroscopy. The changes in PL excitation intensity of the Mn:CdS QDs and PL lifetime of the TPBI clearly demonstrate an efficient energy transfer process from TPBI to QDs in the blend films. Further, it is found that the efficiency of Forster resonance energy transfer increases with the increasing of the thicknesses of CdS shell. These results highlight the potential of Mn doped QDs for fabricating high-performance QD lightemitting diodes. © 2014 The Japan Society of Applied Physics

Increasing the electron emission site density of nanostructured emitters with limited field screening effects is one of the key issues for improving the field emission (FE) properties. In this work, we reported the Au-nanoparticles-density-dependent field emission behaviors of surface-decorated SiC nanowires. The Au nanoparticles (AuNPs) decorated around the surface of the SiC nanowires were achieved via an ion sputtering technique, by which the densities of the isolated AuNPs could be adjusted by controlling the fixed sputtering times. The measured FE characteristics demonstrated that the turn-on fields of the SiC nanowires were tuned to be of 2.06, 1.14, and 3.35 V/μm with the increase of the decorated AuNPs densities, suggesting that a suitable decorated AuNPs density could render the SiC nanowires with totally excellent FE performances by increasing the emission sites and limiting the field screening effects.

The optical properties of heavily Al-doped single-crystal Si3N4 nanobelts are investigated by measuring their absorption, photoluminescence, and photoluminescence excitation spectra. The results suggest that the doped Si3N4 exhibit two absorptions at 2.5 and 4.2 eV, instead of absorption at 5.0 eV in the pure Si3N4. The doped nanobelts show light emissions in a range of 1.4 to 3.6 eV, which is red-shifted as compared with that of pure Si3N4 nanobelts. These results are ascribed to the unique doping mechanism of Al, which generates two types of defects.

The surface dislocation model is used to obtain a method of evaluating the non-local stresses of screw dislocation in a bi-medium. The exact solutions of non-local stresses of screw dislocation are given for two particular cases. All classical singularities are eliminated. Estimates are provided for the critical shear which will produce a single dislocation and for the maximum force on the screw dislocation due to the existing interface.

Novel P‐doped SiC flexible field emitters are developed on carbon fabric substrates, having both low E to of 1.03–0.73 Vμm−1 up to high temperatures of 673 K, and extremely high current emission stability when subjected to different bending states, bending circle times as well as high temperatures (current emission fluctuations are typically in the range ±2.1%–3.4%).

The density of the nanowires is one of the key issues for their field emission (FE) properties of the nanoarrays, since it plays an important role on the electron emission sites and field screening effect. Here, we reported the nanowire-density-dependent FE properties of the n-type 3C-SiC nanoarrays. The highly oriented and large-scale SiC nanoarrays were grown on the 6H-SiC wafer via pyrolysis of polyureasilazane by adjusting the thicknesses of Au films used as the catalysts. The densities of the nanoarrays were tunable to be ∼2.9 × 107, ∼4.0 × 107, and ∼5.7 × 107 nanowires/cm2 by controlling the Au film thicknesses of 50, 70, and 90 nm, respectively. The measured FE characteristics disclosed that the turn-on fields of the samples could be tailored to be of ∼1.79, 1.57, and 1.95 V/μm with the increase of the densities, suggesting that a suitable nanowire density could favor the enhanced electron emission from the SiC nanoarrays with improved emission sites and limited field screening effects.

Poly (vinyl alcohol) (PVA)/H3PMo12O40ultra-fine fiber aggregates contained differential weight percentage of H3PMo12O40 to PVA (20, 50 and 80 wt.%, respectively) have been successfully prepared by electrospinning technique. By means of IR spectrum, wide-angle X-ray diffraction, and scanning electron microscope (SEM) techniques, the fiber aggregates were characterized. The result from scanning electron microscopy (SEM) showed that the average diameter of the fibers was between 240-900 nm. The photochromic behavior of the fiber aggregates was investigated by means of IR, UV-Vis spectra and electron spin resonance (ESR). The results showed that the Mo atom of H3PMo12O40 was reduced via one-electron step and the PVA was oxidized to unsaturated ketone after the PVA/H3PMo12O40 fiber aggregates was irradiated under UV light. The color of the fiber aggregates changed from white to blue under ultraviolet irradiation and the photochromism of the fiber aggregates was reversible in air condition.

Flexible field emission (FE) emitters, whose unique advantages are lightweight and conformable, promise to enable a wide range of technologies, such as roll-up flexible FE displays, e-papers and flexible light-emitting diodes. In this work, we demonstrate for the first time highly flexible SiC field emitters with low turn-on fields and excellent emission stabilities. n-Type SiC nanoneedles with ultra-sharp tips and tailored N-doping levels were synthesized via a catalyst-assisted pyrolysis process on carbon fabrics by controlling the gas mixture and cooling rate. The turn-on field, threshold field and current emission fluctuation of SiC nanoneedle emitters with an N-doping level of 7.58 at.% are 1.11 V μm−1, 1.55 V μm−1 and 8.1%, respectively, suggesting the best overall performance for such flexible field emitters. Furthermore, characterization of the FE properties under repeated bending cycles and different bending states reveal that the SiC field emitters are mechanically and electrically robust with unprecedentedly high flexibility and stabilities. These findings underscore the importance of concurrent morphology and composition controls in nanomaterial synthesis and establish SiC nanoneedles as the most promising candidate for flexible FE applications. Spiky silicon carbide (SiC) ‘nanoneedles’ can improve light emission from e-paper and other bendable electronic devices. Flexible field-emission displays are an emerging technology in which tiny conductive tips grown on lightweight, rollable surfaces generate intense light. Significant manufacturing- and materials-related obstacles, however, have limited their application. Now, a team led by Tom Wu from King Abdullah University of Science and Technology in Saudi Arabia and Weiyou Yang from Ningbo University of Technology in China investigated how SiC — a compound with notable stiffness and stablity — performed as a field emitter by catalytically synthesising this material into nanoscale needles with ultrasharp tips and controllable doping levels on a carbon fabric surface. Their experiments showed that the SiC nanoneedles had low ‘turn-on’ field requirements and minimal emission fluctuations even after repeated bending cycles, thanks to their impressive mechanical robustness. We demonstrated for the first time highly flexible N-doped SiC nanoneedle field emitters with low turn-on fields and excellent emission stabilities. The characterizations of their field emission properties under repeated bending cycles and different bending states confirmed that such emitters are mechanically and electrically robust. These findings underscore the importance of concurrent morphology and composition controls in nanomaterial synthesis and establish SiC nanoneedles as the most promising candidate for flexible FE applications.

Understanding the roles of contacts and interfaces between metals and semiconductors is critically important for exploring nanostructure-based nanodevices. The present study shed some light on the dominated mechanism of size-dependent carrier transfer in the Schottky barrier diodes configured by the Pt-Ir/Si3N4-nanobelt/graphite (metal-semiconductor-metal (MSM)) sandwiched structure via a conductive atomic force microscopy using nanobelts with various thicknesses. The observed I-V behaviors suggested that the charge transports under the low and high biases were dominated by the reverse-biased Schottky barrier and space-charge-limited current (SCLC), respectively. The intermediate region between the low and high biases presented the transition between the Ohmic and SCLC behaviors, in which the ≡Si and =N dangling bonds acted as the defects within the Si3N4 nanobelt surface are predominant in the charge transfer.

In this work, we reported the energy transfer between Mn doped CdS quantum dots (Mn:CdS QDs) with the core–shell structure of MnS/ZnS/CdS and 1,3,5-tris(N-phenylbenz-imidazol-2,yl) benzene (TPBI) in inorganic/organic blend films by steady-state and time-resolved photoluminescence (PL) spectroscopy. The changes in PL excitation intensity of the Mn:CdS QDs and PL lifetime of the TPBI clearly demonstrate an efficient energy transfer process from TPBI to QDs in the blend films. Further, it is found that the efficiency of Förster resonance energy transfer increases with the increasing of the thicknesses of CdS shell. These results highlight the potential of Mn doped QDs for fabricating high-performance QD light-emitting diodes.

While TiO2 nanoparticles are one of the most promising photocatalysts, their applications have been greatly hindered by easy aggregation. One of the effective routes to solve this problem is to incorporate them on/in a solid carrier. In this paper, we report the fabrication of hierarchically porous TiO2/SiO2 fibers via an electrospinning technique combined with subsequent high-temperature calcination treatment, in which the hierarchically porous SiO2 fibers confer a platform to assemble TiO2 nanoparticles with a uniform spatial distribution. The resultant hierarchically porous TiO2/SiO2 fibers have shown an enhanced photocatalytic activity with ∼95% degradation of rhodamine B as compared to ∼75% using our synthesized TiO2 nanoparticles and ∼77% using commercially available Degussa P25 after 120 min illumination.

The synthesis of hollow nanostructures has attracted great attention in nanotechnology. As compared to the long hollow structures, the short counterparts could serve other compelling applications, and have become a hotspot in the field of nanomedicine. In the present work, a novel brand graphite-based nanostructure with a special cup-shaped feature was synthesized via the pyrolysis of a solid carbon source of polymethylmethacrylate (PMMA). These nanocups are typically characterized with open ends, tapered hollow cavities and slowly convergent roots, which are free standing on the graphene films with very low length/diameter aspect ratios as compared to conventional carbon nanotubes. The growth mechanism of these cups was proposed. It is promising that the present graphite nanocups could have potential applications in drug delivery.

It is critically important to limit the oxidation of pure SiC in humid air, especially for mesoporous SiC with large surface areas. One of the effective routes is to introduce an inert outer layer around the surface of SiC to inhibit the formation of the SiOx oxides. In present work, we report the fabrication of mesoporous graphite/SiC hybrid fibers via electrospinning of the polymer precursors containing polyureasilazane, polyvinylpyrrolidone, cetyltrimethylammonium bromide and paraffin oil, combined with subsequent high-temperature pyrolysis treatment. The resultant fibers were systematically characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM) and high-resolution transmission electron microscopy (HRTEM). It is found that the paraffin oil content has a profound effect on the growth of the fibers, enabling the fabrication of mesoporous graphite/SiC hybrid fibers with tunable structures and high purities. It is expected that the introduced graphite could significantly improve the surface properties of SiC mesoporous fibers, which could inspire and enhance their potential applications in photocatalysts and catalyst supports.

We demonstrate a strategy for the growth of Mn2+ ion doped cadmium based II–VI semiconductor quantum dots (QDs) with a designed buffer layer of ZnS (MnS/ZnS/CdS or Mn:CdS QDs), which aims to meet the challenge of obtaining highly efficient and well-resolved Mn2+ ion emission. First, small, high quality MnS cores are obtained by using thiols to replace conventional alkyl amines as capping ligands. Then a buffer layer of ZnS with a tailored thickness is introduced to the QDs before the growth of CdS shells to reduce the size mismatch between the Mn2+ (dopant) and Cd2+ (host) ions. The fabricated MnS/ZnS/CdS core/shell QDs exhibit a high PL QY of up to 68%, which is the highest ever reported for any type of Mn2+ ion doped cadmium based II–VI semiconductor QD. The photoluminescence (PL) of the QDs consists of well-resolved Mn2+ ion emission without any detectable emission from the CdS band edge or surface defects. In addition, our MnS/ZnS/CdS QDs cannot only be made water-soluble, but can also be coated by ligands with short carbon chain lengths, nearly without cost to the PL QY, which could make them strong candidates for practical applications in biology/biomedicine and opto/electronic devices.

The purity and yield issues are significant challenges for the practical applications of nanoheterojunctions in functional devices. In the present work, we report the mass production of SiC/SiOx nanochain heterojunctions via pyrolysis of polymeric precursors. The as-synthesized nanochain heterojunctions were characterized by X-ray diffraction (XRD), field-emission scanning electron microscopy (FESEM) and high-resolution transmission electron microscopy (HRTEM). The composition of the raw materials played a critically important role in the formation of SiC/SiOx nanochain heterojunctions. As compared to the reported works, our synthesized SiC/SiOx nanochain heterojunctions exhibit much higher purities with a very uniform size distribution and fascinating microstructures, which make them promising to be utilized as optoelectronic nanodevices.

In the present work, we report the growth of flexible SiC quasialigned nanoarrays with N dopants on carbon fabric substrate via the catalyst-assisted pyrolysis of a polymeric precursor. The resultant products are systematically characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), high-resolution transmission electron microscopy (HRTEM) and energy-dispersive X-ray spectroscopy (EDS). The as-synthesized SiC nanowires are single-crystalline and grow along the [111] direction with a uniform spatial distribution of N dopants. The effect of the distance between the SiC array and the anode on the Field emission (FE) properties was investigated. FE measurements show that these N-doped SiC nanoarrays could be an excellent candidate for field emitters with very low turn-on fields of 1.90–2.65 V μm−1 and threshold fields of 2.53–3.51 V μm−1, respectively, which can be mainly attributed to the decrease of work function induced by the N dopants.

Doping of one-dimensional silicon carbide nanomaterials with tailored doping types and levels is highly required for their potential applications in functional nanodevices. In the present work, we have reported the synthesis of N-doped 3C–SiC nanowires via catalyst-assisted pyrolysis of polymeric precursors with Co(NO3)2 as the catalysts. The resultant products were systematically characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), high-resolution transmission electron microscopy (HRTEM) and energy spectrum (EDS). It was found that a relatively low partial pressure played a determined role on the introduction of N dopants into the SiC nanowires. The pyrolysis temperatures had a profound effect on the doping levels of N, enabling the tunable n-type doping of 3C–SiC nanowires. Current work suggests a facile technique for the synthesis of n-type SiC nanomaterials with a uniform spatial distribution of N dopants in a controlled manner, which could be useful for manufacturing optoelectric nanodevices.

We reported the piezoresistance behaviors of n-type 3C-SiC nanowires, which show that the present SiC nanowires could be an excellent candidate for building robust pressure sensors with high sensitivities.

Inhibiting the easy oxidation nature of SiC nanostructure surface is a challenge for its application in nanodevices. Here, we have demonstrated the fabrication of C-sheathed SiC nanocables via a designed chemical vapour deposition method, in which the use of a steel-hoop-like sample support favours the growth of SiC/C nanocables with surface modification of C coatings. The obtained SiC/C nanocables are systematically characterized by scanning electron microscopy, x-ray diffraction, transmission electron microscopy and Raman spectroscopy. The electrical property measurements suggest that the surface modification of SiC nanostructures by C coatings can not only modulate the SiC surface property from hydrophilic to hydrophobic, but also significantly enhance their electrical properties.

In this study, we demonstrate the unconventional vapor–liquid–solid (VLS) growth of amorphous SiO2 nanooctopuses. The SiO2 nanooctopuses were successfully synthesized by a simple water-assisted reaction on Si wafers. The obtained aggregates have been systematically characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD), transmission electron microscopy (TEM) and Raman spectroscopy. A novel VLS model has been proposed for the growth of SiO2 nanooctopuses based on the experimental observations and characterizations. The amorphous SiO2 nanooctopuses emit stable violet-blue light, implying their potential applications in photoelectronic devices.

We reported, for the first time, the piezoresistance behaviors of single p-type 6H-SiC nanowires. The results suggest that present p-type 6H-SiC nanowires could be an excellent candidate for the fabrication of robust and reliable stress sensors.

We have demonstrated the growth of asymmetric ordered Si3N4 nanodendrites via the catalyst-assisted pyrolysis of a polymeric precursor. The growth of the unique structure is due to the usage of a co-catalyst composed of a Fe-Al mixture. First, Si3N4 stems grow at an early stage via a gas−solid process with Al being the catalyst. Fe is then selectively deposited on the negatively charged (010) surface of the Si3N4 stem to form catalytic droplets which promote the growth of the ordered nanowire branches. The novel nanostructures could be useful for the fabrication of nanodevices and nanocomposites. The principle demonstrated here is applicable for synthesizing ordered branched nanodendrites in other material systems.

We report the synthesis of aligned ultra-long single-crystalline α-Si(3)N(4) nanowires by pyrolysis of a polymeric precursor without any template. The length of the wires is up to several centimeters, which is significantly longer than that of any Si(3)N(4) wires reported previously. Microscopy characterization reveals that the wires are single crystals, with a uniform diameter of ∼200 nm. Intense visible photoluminescence was observed between 1.3 and 3.7 eV. The wires could be useful in the fabrication of optoelectronic nanodevices and nanocomposites.